Nicholas Rasmussen, who headed the intelligence organisation for three years, will leave in December.

Nicholas Rasmussen, the head of the US National Counterterrorism Center, has announced that he is leaving his post at the end of the year.

Rasmussen is stepping down after serving for more than three years as the leader of one of the country's newest intelligence organisations, founded after the attacks on September, 11, 2001.

The National Counterterrorism Center serves as a coordination hub for all intelligence related to "terrorism", both foreign and domestic. It produces intelligence and threat analysis, maintains a database of known and suspected "terrorists" in the US and around the world, and conducts strategic operational planning across the intelligence community.

In a statement, US Director of National Intelligence Dan Coats described Rasmussen as "deeply committed to the counterterrorism mission", noting that he "has skillfully guided the nation through an evolving and complex terrorism threat environment".

Rasmussen has served through the Bush, Obama and Trump administrations in various senior roles related to the country's "counterterrorism" efforts.

Commenting on the evolving nature of "terrorism", including the threat of cyber-attacks, Rasmussen said in a recent interview with The Cipher Brief that "the discipline of counterterrorism is literally evolving and changing under our feet every day".

Until President Donald Trump nominates a successor, the National Counterterrorism Center's deputy director, Russ Travers, will begin serving as acting director in late December.